1. Field of the Invention
The invention relates in general to a reflection mirror support structure, and more particularly, to a reflection mirror support structure used in an optical scanner.
2. Description of the Related Art
The conventional optical scanner as illustrated in FIG. 1 has a light source 100, a reflection mirror set 400, a lens 500, an enclosure 900 and an optical sensor such as a charge couple device (CCD) 600. While performing scanning, light from the light source 100 is incident onto a document 200 to obtain an image light by reflection or transmission. The reflection mirror set 400 comprises several reflection mirrors 401, 402, 403 and is located in an optical path of the image light. The image of document 200 on the light transmissible plate 300 is directed to the reflection mirror set 400 and reflected to the lens 500 by the reflection mirror set 400. The lens 500 can receive the image light of the document 200 transmitted by the reflection mirror set 400 and display the image light on the charge couple device 600.
The conventional method of mounting the reflection mirror is shown in FIG. 2. The enclosure 900 inside the optical scanner contains therein a pair of vertical planes and a pair of parallel supporting seats 700 is formed thereon. Each supporting surface 705 for holding the carrier seats 700 has a projecting rib 701, while the bottom surface of both ends of the reflection mirror 401 are in line contact with the projecting ribs 701 on the supporting surfaces 705 and are held thereby. After adjusting the position of the reflection mirror 401, a tool such as a pair of tongs is used to attach the two ends of the reflection mirror 401 to the two carrier seats.
When the carrier seats 700 and the enclosure 900 of the optical scanner are integrated by injection molding, the supporting seats 700 are easily formed unparallel to each other due to poor conditions of injection molding. Under such circumstances, the reflection mirror 401 attached to the supporting seats 700 is easily twisted and deformed to manifest an unstable angle. Further, angle variation easily occurs during shifting or transportation to cause the image dislocation, which affects the image quality.
The invention provides a reflection mirror support structure applied to the reflection mirror of an optical scanner. Using three points or a single point and a line to construct a plane, the reflection mirror is held. The image distortion caused by bending the reflection mirror or twisted deformation because of an unparallel surface angle is improved.
The reflection mirror holding structure located in a scan module bulk enclosure inside of an optical scanner holds at least one reflection mirror. The reflection mirror support structure comprises a first supporting seat, a second supporting seat and at least a fastener. The first supporting seat is formed on the scan module bulk enclosure. The first supporting seat has a supporting surface, on which a projecting rib is formed. The second supporting seat is formed on the scan module bulk surface. The second supporting seat has a supporting surface on which a projecting rib is formed. The supporting surfaces of the first and second supporting seats are level with each other. The heights of projecting ribs on the first and the second supporting surfaces are the same, while the projecting ribs of the first and the second supporting surfaces extend perpendicular to each other. The fastener is used to fasten and attach two ends of the reflection mirror to the first and second supporting seats, respectively. The bottom surfaces of the two ends of the reflection mirror are respectively in contact with the projecting ribs of the first and the second supporting seats, while these two projecting ribs are in point and line contact.
The invention further provides another reflection mirror support structure located in a scan module bulk enclosure of an optical scanner to hold at least one reflection mirror. The reflection mirror support structure comprises a first supporting seat, a second supporting seat, and at least one fastening member. The first supporting seat formed on the scan module bulk enclosure has a supporting surface, on which a projecting point is formed. The second supporting. seat formed on the scan module bulk enclosure has a supporting surface, on which two projecting points are formed. The supporting surface of the second supporting seat is on a same plane of the supporting surface of the first supporting seat, and the projecting point of the first supporting seat is not on the line drawn between the projecting points on the second supporting seat. The fastening member is used to attach two ends of the reflection mirror to the first and the second supporting seats. When the reflection mirror is attached to the first and the second supporting seats, the bottom surfaces of the two ends of the reflection mirror are respectively in contact with the projecting points on the second supporting seat and the first supporting seat. The contacts for the projecting points of the second and first supporting seat are in a form of point contact.
Accordingly, perpendicularly projecting ribs are formed on two supporting seats, and the theory for forming a plane with a point and a line is applied to attach the reflection mirror to the two supporting seats. Thus constructed, the supporting seats are parallel to each, and twisting deformation is eliminated.
Further, a projecting rib and two projecting points are formed on two supporting seats, respectively. The theory of forming a plane with three points is applied to attache the reflection mirror to the two supporting seats. Thus, the supporting seats are parallel to each, and the twisting deformation is eliminated.
Further, a projecting point and two projecting points are formed on two supporting seats, respectively. The theory of forming a plane with three points is applied to attach the reflection mirror to the two supporting seats. Thus, the supporting seats are parallel to each, and the twisting deformation is eliminated.
Both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.